Data session continuity between wireless networks

ABSTRACT

Embodiments disclosed herein provide systems and methods to provide data session continuity between wireless networks. In a particular embodiment, a method provides receiving a request to create a data session for a wireless communication device exchanging communications with a wireless local area network via a wireless access point. The method further provides determining an access point identifier for the wireless access point and selecting a control system for a cellular communication network of a plurality of cellular communication networks based on the access point identifier. The method further provides anchoring the data session to the control system.

RELATED CASES

This patent application is a continuation of U.S. patent application13/555,397 that was filed on Jul. 23, 2012 and that is entitled “DATASESSION CONTINUITY BETWEEN WIRELESS NETWORKS.” U.S. patent applicationSer. No. 13/555,397 is hereby incorporated by reference into this patentapplication.

TECHNICAL BACKGROUND

The use of cellular communication networks to exchange datacommunications with wireless devices can be supplemented with wirelesslocal area networks (LANs), such as a personal WIFI network. The use ofwireless LANs over cellular communication networks is beneficial becausea wireless LAN may provide faster data transfer speeds and is notsubject to a cellular network operator's bandwidth usage restrictions,among other reasons. Thus, a wireless device capable of communicatingwith wireless LANs and cellular networks will typically select awireless LAN for data communications when a wireless LAN is accessible.

However, wireless LANs usually have a much smaller wireless signalcoverage area when compared to cellular communication networks.Accordingly, a wireless device may easily move beyond the coverage areaof a wireless LAN, which necessitates the use of a cellularcommunication network to exchange data communications. Since wirelessLANs and cellular networks use different gateways to provide access tothe internet, a wireless device in the middle of a data communicationsession will lose the data session when the device moves from a wirelessLAN to a cellular network.

OVERVIEW

Embodiments disclosed herein provide systems and methods to provide datasession continuity between wireless networks. In a particularembodiment, a method provides receiving a request to create a datasession for a wireless communication device exchanging communicationswith a wireless local area network via a wireless access point. Themethod further provides determining an access point identifier for thewireless access point and selecting a control system for a cellularcommunication network of a plurality of cellular communication networksbased on the access point identifier. The method further providesanchoring the data session to the control system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a wireless communication system to provide datasession continuity between wireless networks.

FIG. 2 illustrates the operation of the wireless communication system toprovide data session continuity between wireless networks.

FIG. 3 illustrates a wireless communication system to provide datasession continuity between wireless networks.

FIG. 4 illustrates the operation of the wireless communication system toprovide data session continuity between wireless networks.

FIG. 5 illustrates the operation of the wireless communication system toprovide data session continuity between wireless networks.

FIG. 6 illustrates the operation of the wireless communication system toprovide data session continuity between wireless networks.

FIG. 7 illustrates an SSID anchor table to provide data sessioncontinuity between wireless networks.

FIG. 8 illustrates a communication control system to provide datasession continuity between wireless networks.

DETAILED DESCRIPTION

The following description and associated figures teach the best mode ofthe invention. For the purpose of teaching inventive principles, someconventional aspects of the best mode may be simplified or omitted. Thefollowing claims specify the scope of the invention. Note that someaspects of the best mode may not fall within the scope of the inventionas specified by the claims. Thus, those skilled in the art willappreciate variations from the best mode that fall within the scope ofthe invention. Those skilled in the art will appreciate that thefeatures described below can be combined in various ways to formmultiple variations of the invention. As a result, the invention is notlimited to the specific examples described below, but only by the claimsand their equivalents.

FIG. 1 illustrates wireless communication system 100. Wirelesscommunication system 100 includes wireless communication device 101,wireless local area network (LAN) 102, cellular communication network103, cellular communication network 104, communication control system105, communication control system 106, and data network 107. Wirelesscommunication device 101 and wireless LAN 102 communicate over wirelesslink 111. Wireless communication device 101 and cellular communicationnetwork 103 communicate over wireless link 112. Wireless communicationdevice 101 and cellular communication network 104 communicate overwireless link 113. Wireless LAN 102 and data network 107 communicateover communication link 114. Cellular communication network 103 and datanetwork 107 communicate over communication link 115. Cellularcommunication network 104 and data network 107 communicate overcommunication link 116.

In operation, wireless device 101 is a multimode device that is capableof communicating wirelessly with wireless LAN 102 and cellular networks103-104. For example, wireless device 101 may use Wireless Fidelity(WIFI) or some other wireless LAN protocol to communicate with wirelessLAN 102. Wireless device 101 may use Code Division Multiple Access(CDMA), Evolution Data Only (EVDO), Worldwide Interoperability forMicrowave Access (WIMAX), Global System for Mobile Communication (GSM),Long Term Evolution (LTE), High Speed Packet Access (HSPA), or someother cellular wireless communication protocol to communicate with eachof cellular networks 103-104. Wireless device 101 may use the samecellular protocol to communicate with cellular network 103 as wirelessdevice 101 uses to communicate with cellular network 104 or may use adifferent protocol for each network.

Typically, even when using multiple wireless access points, wireless LAN102 has a much smaller wireless coverage area than cellular networks103-104. However, when wireless device 101 is within the coverage areaof wireless LAN 102 it may be advantageous for wireless device 101 toexchange data communications with wireless LAN 102 rather than cellularnetworks 103-104. For example, wireless LAN 102 may provide faster datacommunications than can cellular networks 103-104, may not be subject tobandwidth usage limitations of cellular networks 103-104, may not besubject to bandwidth usage costs of cellular networks 103-104, mayprovide access to services that are local to wireless LAN 102, or forany other reason.

Furthermore, when not located within the coverage area of wireless LAN102, wireless device 101 may exchange data communications with one ofcellular networks 103-104 over the other for similar reasons as thoselisted above for wireless LAN 102. Additionally, wireless device 101 mayexchange communications with one cellular network over the other due tothe wireless coverage area limitations of each cellular network 103-104,due to one cellular network having better signal strength, due to onecellular network requiring the use of less power of wireless device 101to communicate, or for any other reason that one cellular network wouldbe selected over another.

When wireless device 101 exchanges communications with data network 107,wireless device 101 is assigned an identifier, such as an IP address,that will direct data communications from data network 101 to wirelessdevice 101. In particular, wireless LAN 102, control system 105, andcontrol system 106 can each assign the identifier to wireless device 101when wireless device 101 is accessing data network 107 through wirelessLAN 102, cellular network 103, or cellular network 104, respectively. Ifwireless device 101 were to switch from communicating with wireless LAN102 to communicating with one of cellular networks 103-104, thenwireless device 101 would be assigned a new identifier by control system105 or 106. Consequently, any data session communications from datanetwork 107 directed to the identifier for wireless device 101 onwireless LAN 102 would be lost after wireless device 101 switchesnetworks. The data session communications would be lost because theidentifier assigned to wireless device 101 by wireless LAN 102 will nolonger be able to direct data communications to wireless device 101.

FIG. 2 illustrates the operation of wireless communication system 100 toprovide data session continuity between wireless networks. The methoddescribed in FIG. 2 may be performed by control system 105, controlsystem 106, or by some other control system located in cellularcommunication network 103, cellular communication network 104, datanetwork 107, or elsewhere.

The operation begins when a request is received to create a data sessionfor wireless device 101 exchanging communications with a wireless LAN102 via a wireless access point (step 200). The request may be receivedwhen wireless device 101 registers with wireless LAN 102 in order toexchange data communications with data network 107. Accordingly, thedata session may include all data communications exchanged over wirelessLAN 102. Wireless device 101 may register with wireless LAN 102automatically when entering the wireless coverage area, upon beingdirected to by a user of wireless device 101, upon a wireless LAN radiowithin wireless device 101 being activated, or for any other reason.

Alternatively, the request may be received at a point in time afterwireless device 101 has registered with wireless LAN 102. Thus, therequest may be received when a session for a particular data service isrequested. The data session may be for any type of data service that canbe provided to wireless device 101 over data network 107 and wirelessLAN 102, such as web browsing, email, VoIP, audio, video, file transfer,or any other type of data service. The request in this example may haveoriginated from wireless device 101 or from some other system, such as aservice system on data network 107 that provides wireless device 101with a service.

After receiving the request, an access point identifier is determinedfor the wireless access point (step 202). The access point identifiermay identify the wireless access point individually, a group of wirelessaccess points, or wireless LAN 102. For example, if wireless LAN 102 isa WIFI network, then the access point identifier may be a service setidentifier (SSID) for the WIFI network. The access point identifier maybe included in the request if the request originated from wirelessdevice 101, requested from wireless device 101, requested from wirelessLAN 102, or by any other method.

One of control systems 105-106 for cellular networks 103-104,respectively, is selected based on the access point identifier (step204). Specifically, the location of wireless LAN 102 is identified fromthe access point identifier. The location may be identified from a datastructure containing access point identifiers and correspondinglocations. The location may be expressed in the form of geographiccoordinates, address, city, state, county, zip code, or any other way ofexpressing a location.

Since wireless device 101 is communicating with wireless LAN 102, it canbe assumed that the location of wireless LAN 102 is also the approximatelocation of wireless device 101. Thus, once the location of wireless LAN102 is determined, it can then be determined which of cellular networks103 and 104 will most likely exchange data communications with wirelessdevice 101 when wireless device 101 stops exchanging data communicationswith wireless LAN 102.

Reasons for determining one cellular network over the other may includeone cellular network does not provide sufficient wireless coverage atthe location of wireless LAN 102, one cellular network provides fasterdata exchange speeds, one cellular network is preferred by wirelessdevice 101, wireless device 101 does not have the radio necessary tocommunicate with one cellular network (or that radio is turned off), orfor any other reason that one cellular network would be chosen overanother.

The control system that is selected is the control system of controlsystems 105-106 that corresponds to which of cellular networks 103-104is determined as being mostly likely to exchange data communicationswith wireless device 101 when wireless device 101 stops exchanging datacommunications with wireless LAN 102.

In some embodiments, selecting a control system may be simplified toquerying a data structure that containing access point identifiers and acorresponding cellular network or, more specifically, control systemthat should be used at a location for each of the access pointidentifiers. The data structure may further include information aboutwireless device 101, such as cellular network preferences and cellularnetwork capabilities, so that a control system can be selected that isbest suited for wireless device 101 at the location.

Once the control system is selected, the data session is anchored to thecontrol system (step 106). For the purposes of this example, controlsystem 105 is selected as being most likely to exchange datacommunications with wireless device 101. To anchor the data session withcontrol system 105, control system 105 configures itself to be anintermediate system between wireless LAN 102 and data network 107 on apath for data communications exchanged between wireless device 101 anddata network 107 for the data session.

In one embodiment, the data session is anchored to control system 105using the following process. Wireless LAN 102 assigns a first identifierto wireless device 101 for exchanging data communications. Controlsystem 105 uses this identifier to direct communications to wirelessdevice 101 via data network 107 and wireless LAN 102. Control system 105assigns a second identifier to wireless device 101 for the data session.This second identifier is used by whatever system(s) on data network 107to transfer data to wireless device 101 for the data session.Accordingly, the second identifier directs data session communicationsto control system 105 using the second identifier. Control system 105then forwards the data session communications to wireless device 101using the first identifier that was assigned by wireless LAN 102. Thus,any system that transfers data to wireless device 101 from data network107 will transfer that data through control system 105. Similarly,wireless device 101 may direct any communications for the data sessionto the address of control system 105 so that control system 105 can actas an intermediary in the uplink direction as well.

After the data session is anchored, wireless device 101 may stopexchanging communications with wireless LAN 102 and start exchangingcommunications with cellular network 103 during the data session. Forexample, the user of wireless device 101 may move wireless device 101from a building where wireless LAN 102 provides wireless networkcoverage. Having the data session anchored to control system 105 allowsthe data session to continue uninterrupted because data communicationsfrom wireless device 101 on cellular network 103 pass through controlsystem 105 by default. Moreover, since data communications for the datasession were already being routed through control system 105 from datanetwork 107, control system 105 will still be able to forward thosecommunications to wireless device 101 through cellular network 103rather than wireless LAN 102.

Advantageously, the method presented in FIG. 2 allows the data sessionto be maintained when wireless device 101 stops communicating withwireless LAN 102 and starts communicating with cellular network 103while in the middle of a data session.

In some embodiments, wireless LANs or cellular communication networksmay exist along with additional control systems. Also, a single controlsystem may function for multiple cellular networks rather than for asingle cellular network as depicted in FIG. 1.

Referring back to FIG. 1, wireless communication device 101 comprisesRadio Frequency (RF) communication circuitry and an antenna. The RFcommunication circuitry typically includes an amplifier, filter,modulator, and signal processing circuitry. Wireless communicationdevice 101 may also include a user interface, memory device, software,processing circuitry, or some other communication components. Wirelesscommunication device 101 may be a telephone, computer, e-book, mobileInternet appliance, wireless network interface card, media player, gameconsole, or some other wireless communication apparatus—includingcombinations thereof.

Wireless LAN 102 and cellular communication networks 103-104 eachcomprise network elements that provide communications services towireless device 101. Wireless LAN 102 and cellular communicationnetworks 103-104 may comprise switches, wireless access nodes, Internetrouters, network gateways, application servers, computer systems,communication links, or some other type of communicationequipment—including combinations thereof.

Communication control systems 105-106 each comprise a computer systemand communication interface. Communication control systems 105-106 mayalso include other components such a router, server, data storagesystem, and power supply. Communication control systems 105-106 mayreside in a single device or may be distributed across multiple devices.Communication control systems 105-106 could be a packet data networkgateway (PGW), home agent, mobile switching center, network gatewaysystem, Internet access node, application server, service node, or someother communication system—including combinations thereof.

Data network 107 comprises network elements that provide communicationsservices to wireless device 101. Data network 107 may comprise switches,wireless access nodes, Internet routers, network gateways, applicationservers, computer systems, communication links, or some other type ofcommunication equipment—including combinations thereof.

Wireless links 111-113 use the air or space as the transport media.Wireless links 111-113 may use various protocols, such as Code DivisionMultiple Access (CDMA), Evolution Data Only (EVDO), WorldwideInteroperability for Microwave Access (WIMAX), Global System for MobileCommunication (GSM), Long Term Evolution (LTE), Wireless Fidelity(WIFI), High Speed Packet Access (HSPA), or some other wirelesscommunication format. Communication links 114-116 use metal, glass, air,space, or some other material as the transport media. Communicationlinks 114-116 could use various communication protocols, such as TimeDivision Multiplex (TDM), Internet Protocol (IP), Ethernet,communication signaling, CDMA, EVDO, WIMAX, GSM, LTE, WIFI, HSPA, orsome other communication format—including combinations thereof.Communication links 114-116 could be direct links or may includeintermediate networks, systems, or devices.

FIG. 3 illustrates wireless communication system 300. Wirelesscommunication system 300 includes wireless communication device 301,WIFI network 302, LTE cellular network 303, CDMA cellular network 304,WIMAX cellular network 305, packet data network gateway (PGW) 306, homeagent 307, authentication, authorization, and accounting server (AAA) orhome subscriber server (HSS) 308, and Internet 309.

Wireless communication device 301 and WIFI network 302 communicate overwireless link 311. Wireless communication device 301 and LTE network 303communicate over wireless link 312. Wireless communication device 301and CDMA network 304 communicate over wireless link 313. Wirelesscommunication device 301 and WIMAX network 305 communicate over wirelesslink 314. LTE network 303 and PGW 306 communicate over communicationlink 315. CDMA network 304 and home agent 307 communicate overcommunication link 316. WIMAX network 305 and home agent 307 communicateover communication link 317. PGW 306 and AAA/HSS 308 communicate overcommunication link 318. Home agent 307 and AAA/HSS 308 communicate overcommunication link 319. AAA/HSS 308 and Internet 309 communicate overcommunication link 320. WIFI network 302 and Internet 309 communicateover communication link 321.

In operation, WIFI network 302 covers a much smaller area than one ofcellular networks 303-304. For example, an access node of WIFI network302 may be capable of covering a single-family residence while a basestation of cellular networks 303-305 may be able to cover an entireneighborhood where the residence is located and are based ontechnologies that allow communications to be handed off from one basestation to another. Given the smaller coverage area of WIFI network 302,it is likely that wireless device 301 could leave the coverage area ofWIFI network 302 and need to rely on one of cellular networks 303-305for data communications.

FIG. 4 illustrates the operation of wireless communication system 300 toprovide data session continuity between wireless networks. AAA/HSS 308receives a data session request from wireless device 301 (step 400).Wireless device 301 communicates with AAA/HSS 307 over Internet 309 viaWIFI network 302. The data session request may be for any type of dataservice, such as web browsing, email, VoIP, audio, video, file transfer,etc.

AAA/HSS 308 determines the SSID of WIFI network 302 (step 402). TheAAA/HSS 308 may determine the SSID by querying wireless device 301 orWIFI network 302 for the SSID, by receiving the SSID within the datasession request or some other message from wireless device 301 or WIFInetwork 302, or by any other method that one system may determineinformation about another system.

AAA/HSS 308 then determines the location of WIFI network 302 (step 404).The location may be expressed in the form of geographic coordinates,address, city, state, county, zip code, or any other way of expressing alocation. AAA/HSS 308 may have access to a data structure that includesWIFI network SSIDs and a corresponding location to each SSID or may usesome other method of determining the SSID.

After determining the location of WIFI network 302, AAA/HSS 308 selectsa cellular network that serves the location of WIFI network 302 (step406). AAA/HSS 308 may use various criteria for selecting the cellularnetwork including strength of wireless signal for each cellular networkat the location, data speed provided by each cellular network, whetherwireless device 301 is configured to access each cellular network,cellular network preferences for wireless device 301, or any othercriteria that may be useful when selecting a cellular network—includingcombinations thereof.

Once the cellular network is selected, AAA/HSS 308 anchors the datasession to the data communication management system for the chosencellular network. Accordingly, if LTE network 303 is chosen, thenAAA/HSS 308 anchors the data session to PGW 307 (step 408). If eitherCDMA network 304 or WIMAX network 305 is chosen, then AAA/HSS 308anchors the data session to home agent 307 (step 410). While FIG. 3illustrates that AAA/HSS 308 is an intermediate system on data pathsbetween Internet 309 and both PGW 306 and home agent 307, PGW 306 andhome agent 307 may communicate with Internet 307 without AAA/HSS 308acting as an intermediate system.

It should be understood that the data session request received in step400 does not necessarily need to be received before anchoring. Rather,steps 402-410 may occur at a time before wireless device 301 requests adata session. Steps 402-410 may therefore occur at the time wirelessdevice 301 registers with WIFI network 302 or at some time afterregistering. For example, upon registering with WIFI network 302,AAA/HSS 308 is notified that wireless device 301 needs an anchor. Thenotification may come in the form of a message from wireless device 301indicating the SSID of WIFI network 302. Once that message is received,AAA/HSS 302 performs steps 402-410. After those steps are performed,wireless device 301 makes the data session request via WIFI network 302and the data session request is serviced at the already selected anchorpoint.

FIG. 5 is a sequence diagram illustrating the operation of wirelesscommunication system 300 to provide data session continuity betweenwireless networks. The sequence begins with wireless device 301transferring an anchor request to AAA/HSS 308. The anchor request may beto start a data session, such as a web page request, email inbox fetch,media download, etc., or may simply indicate to AAA/HSS 308 thatwireless device 301 is requesting an anchor for a data session that willoccur after the anchor has been assigned. The anchor request istransferred to Internet 309 via WIFI network 302 that provides wirelessdevice 301 with access to Internet 309. Wireless device 301 transfersthe SSID of WIFI network 302 along with the data session request.

Upon receiving the anchor request with the SSID, AAA/HSS 308 referencesSSID anchor table 700, shown in FIG. 7, to determine an anchor point forwireless device 301. SSID anchor table 700 lists a number of SSIDs in afirst column and an anchor system for each SSID in a second column. Inthis example, the SSID of WIFI network 302 is ‘B’ and SSID anchor table700 indicates that PGW 306 should be the anchor. Table 700 may list PGW306 because LTE network 303 is the fastest data network that covers thelocation where WIFI network 302 is located.

In some embodiments, SSID anchor table 700 may further include alocation corresponding to each SSID, whether another anchor isavailable, or any other information that may be pertinent whendetermining an anchor point. For example, wireless device 301 mayfurther indicate, or AAA/HSS 308 otherwise determines, radio networkcapabilities of wireless device 301. In particular, wireless device 301may not have a radio capable of connecting to LTE network 303 or doesnot have that radio functioning at the time of the data session request.In that case, though table 700 provides that PGW 306 as the anchor pointfor SSID ‘B’, AAA/HSS 308 will determine that home agent 307 should bethe anchor rather than PGW 306, which is a control system for a networkwireless device 301 is unable to access.

Continuing with the sequence of FIG. 5, AAA/HSS 308 transfers anchorinformation to wireless device 301 indicating that PGW 306 is the anchorfor data sessions from wireless device 301. The anchor information mayinclude an IP address for PGW 306 to which wireless device 301 willdirect data session traffic. AAA/HSS 308 may further transfer a messageto PGW 306 that notifies PGW 306 that wireless device 301 will be usingPGW 306 as an anchor.

Upon receiving the anchor information, wireless device 301 uses theanchor information to register with PGW 306. Wireless device 301transfers a registration message to PGW 306. In response to receivingthe registration message, PGW 306 registers wireless device 301 so thatPGW 306 can act as an intermediate system on the communication pathbetween wireless device 301 and service systems on Internet 309. Afterregistering with PGW 306, wireless device 301 can exchange datacommunications with systems over Internet 309 via WIFI network 302 andPGW 306. To perform as an anchor system, PGW 306 may handle datacommunications from wireless device 301 to a system on Internet 309 inthe same manner that PGW 306 would if PGW 306 received the datacommunications from wireless device 301 over LTE network 303. However,instead of routing data communications directed to wireless device 301over LTE network 303, PGW 306 routes those communications to the IPaddress of wireless device 301 on WIFI network 302.

In a particular example, wireless device 301 requests a streaming videofrom a streaming video system having an IP address. The data request forthe streaming video at the video system's IP address is transferred in amessage directed to the IP address of PGW 306. Upon receipt of the datasession request, PGW 306 forwards the data session request on to the IPaddress of the video system. The video system responds to the request bytransferring the streaming video data to PGW 306, which then forwardsthe streaming video data to wireless device 301 on WIFI network 302based on an identifier for wireless device 301 on WIFI network 302.

During the transfer of the streaming video, wireless device 301 stopscommunicating with WIFI network 302. This may be caused by wirelessdevice 301 leaving the coverage area of WIFI network 302, by shuttingoff the WIFI radio of wireless device 301, a malfunction of WIFI network302, or for any other reason. Wireless device 301 then connects to LTEnetwork 303 to continue exchanging data communications. Since wirelessdevice 301 is already registered with PGW 306, PGW 306 will recognizethat wireless device 301 left WIFI network 302 and begin transferringthe video data over LTE network 303 to wireless device 301 rather thanover WIFI network 302.

If, however, wireless device 301 connects to either CDMA network 304 orWIMAX network 305 to exchange communications, then the video datasession will be lost because data communications for wireless device 301were not anchored with home agent 307. Wireless device 301 willtherefore need to reestablish the video data session through home agent308.

FIG. 6 is a sequence diagram illustrating the operation of wirelesscommunication system 300 to provide data session continuity betweenwireless networks. The sequence begins with wireless device 301transferring an anchor request to AAA/HSS 308. The anchor request may beto start a data session, such as a web page request, email inbox fetch,media download, etc., or may simply indicate to AAA/HSS 308 thatwireless device 301 is requesting an anchor for a data session that willoccur after the anchor has been assigned. The anchor request istransferred to Internet 309 via WIFI network 302 that provides wirelessdevice 301 with access to Internet 309. Wireless device 301 transfersthe SSID of WIFI network 302 along with the data session request.

Upon receiving the anchor request with the SSID, AAA/HSS 308 referencesSSID anchor table 700, shown in FIG. 7, to determine an anchor point forwireless device 301. SSID anchor table 700 lists a number of SSIDs in afirst column and an anchor system for each SSID in a second column. Inthis example, the SSID of WIFI network 302 is ‘C’ and SSID anchor table700 indicates that home agent 307 should be the anchor. Table 700 maylist home agent 307 because CDMA network 304 is the only cellularnetwork available at the location of WIFI network 302.

AAA/HSS 308 then transfers anchor information to wireless device 301indicating that home agent 307 is the anchor for data sessions fromwireless device 301. The anchor information may include an IP addressfor home agent 307 to which wireless device 301 will direct data sessiontraffic. AAA/HSS 308 may further transfer a message to home agent 307that notifies home agent 307 that wireless device 301 will be using homeagent 307 as an anchor.

Upon receiving the anchor information, wireless device 301 uses theanchor information to register with home agent 307. Wireless device 301transfers a registration message to home agent 307. In response toreceiving the registration message, home agent 307 registers wirelessdevice 301 so that home agent 307 can act as an intermediate system onthe communication path between wireless device 301 and service systemson Internet 309. After registering with home agent 307, wireless device301 can exchange data communications with systems over Internet 309 viaWIFI network 302 and home agent 307. To perform as an anchor system,home agent 307 may handle data communications from wireless device 301to a system on Internet 309 in the same manner that home agent 307 wouldif home agent 307 received the data communications from wireless device301 over CDMA network 304. However, instead of routing datacommunications directed to wireless device 301 over CDMA network 304,home agent 307 routes those communications to the IP address of wirelessdevice 301 on WIFI network 302.

In a particular example, wireless device 301 requests a voice over IP(VoIP) call to a destination on Internet 309. The call request istransferred in a message directed to the IP address of home agent 307.Upon receipt of the call request, home agent 307 forwards the callrequest on to the IP address of the destination. The destinationresponds to the request by transferring a response to the request andany other call data from thereon to home agent 307, which then forwardsthe call data to wireless device 301 on WIFI network 302. Furthermore,any call data transferred from wireless device 301 is transferred to thedestination through home agent 307 in a manner similar to that used forthe call request.

During the exchange of call communications, wireless device 301 stopscommunicating with WIFI network 302. This may be caused by wirelessdevice 301 leaving the coverage area of WIFI network 302, by shuttingoff the WIFI radio of wireless device 301, a malfunction of WIFI network302, or for any other reason. Wireless device 301 then connects to CDMAnetwork 304 to continue exchanging data communications. Since wirelessdevice 301 is already registered with home agent 307, home agent 307will recognize that wireless device 301 left WIFI network 302 and begintransferring call data over CDMA network 304 to wireless device 301rather than over WIFI network 302.

FIG. 8 illustrates communication control system 800. Communicationcontrol system 800 is an example of the communication control systemdiscussed with respect to FIG. 2 or AAA/HSS 308, although the controlsystem and AAA/HSS 308 may use alternative configurations. Communicationcontrol system 800 comprises communication interface 801, user interface802, and processing system 803. Processing system 803 is linked tocommunication interface 801 and user interface 802. Processing system803 includes processing circuitry 805 and memory device 806 that storesoperating software 807.

Communication interface 801 comprises components that communicate overcommunication links, such as network cards, ports, RF transceivers,processing circuitry and software, or some other communication devices.Communication interface 801 may be configured to communicate overmetallic, wireless, or optical links. Communication interface 801 may beconfigured to use TDM, IP, Ethernet, optical networking, wirelessprotocols, communication signaling, or some other communicationformat—including combinations thereof.

User interface 802 comprises components that interact with a user. Userinterface 802 may include a keyboard, display screen, mouse, touch pad,or some other user input/output apparatus. User interface 802 may beomitted in some examples.

Processing circuitry 805 comprises microprocessor and other circuitrythat retrieves and executes operating software 807 from memory device806. Memory device 806 comprises a non-transitory storage medium, suchas a disk drive, flash drive, data storage circuitry, or some othermemory apparatus. Operating software 807 comprises computer programs,firmware, or some other form of machine-readable processinginstructions. Operating software includes identifier determinationmodule 808 and control system selection module 809. Operating software807 may further include an operating system, utilities, drivers, networkinterfaces, applications, or some other type of software. When executedby circuitry 805, operating software 807 directs processing system 803to operate communication control system 800 as described herein.

In particular, operating software 807 directs processing system 803 toreceive a request via communication interface 801 to create a datasession for a wireless communication device exchanging communicationswith a wireless local area network via a wireless access point.Identifier determination module 808 directs processing system 803 todetermine an access point identifier for the wireless access point.Control system selection module 809 directs processing system 803 toselect a control system for a cellular communication network of aplurality of cellular communication networks based on the access pointidentifier and anchor the data session to the control system.

The above description and associated figures teach the best mode of theinvention. The following claims specify the scope of the invention. Notethat some aspects of the best mode may not fall within the scope of theinvention as specified by the claims. Those skilled in the art willappreciate that the features described above can be combined in variousways to form multiple variations of the invention. As a result, theinvention is not limited to the specific embodiments described above,but only by the following claims and their equivalents.

What is claimed is:
 1. A method of operating a wireless communicationsystem, comprising: in a Wireless Fidelity (WiFi) network, receiving aninternet access request from a wireless communication device andresponsively transferring an anchor request to a Long Term Evolution(LTE) network; in the LTE network, receiving the anchor request andresponsively processing a WiFi network identifier to select an LTEPacket Gateway (PGW) and obtaining an internet address for the wirelesscommunication device; in the WiFi network and the LTE network,exchanging first user data between the wireless communication device andan internet through the LTE PGW using the internet address; in the LTEnetwork, after the wireless communication device terminatescommunications with the WiFi network, exchanging second user databetween the wireless communication device and the internet through theLTE P-GW using the internet address but not the WiFi network.
 2. Themethod of claim 1 wherein the internet address used to exchange thefirst user data and the internet address used to exchange the seconduser data comprise a same internet address.
 3. The method of claim 1wherein the WiFi network identifier comprises a Service Set Identifier(SSID).
 4. The method of claim 1 wherein processing the WiFi networkidentifier to select the LTE Packet Gateway (PGW) comprises translatingthe WiFi network identifier into a geographic location of the WiFinetwork and translating the geographic location into a PGW identifier.5. The method of claim 1 wherein processing the WiFi network identifierto select the LTE Packet Gateway (PGW) comprises translating a ServiceSet Identifier (SSID) for the WiFi network into a PGW identifier.
 6. Themethod of claim 1 further comprising, in the LTE network, processing awireless communication device identifier in addition to the WiFi networkidentifier to select the LTE Packet Gateway (PGW).
 7. The method ofclaim 1 wherein the wireless communication device terminatescommunications with the WiFi network in response to leaving WiFi networkcoverage.
 8. The method of claim 1 wherein the wireless communicationdevice terminates communications with the WiFi network in response to auser instruction to disable a WiFi transceiver.
 9. The method of claim 1wherein the first user data and the second user data comprise a voicesession.
 10. The method of claim 1 wherein the first user data and thesecond user data comprise a video session.
 11. A wireless communicationsystem, comprising: a Wireless Fidelity (WiFi) network configured toreceive an internet access request from a wireless communication deviceand responsively transfer an anchor request to a Long Term Evolution(LTE) network; the LTE network configured to receive the anchor requestand responsively process a WiFi network identifier to select an LTEPacket Gateway (PGW) and obtain an internet address for the wirelesscommunication device; the WiFi network and the LTE network configured toexchange first user data between the wireless communication device andan internet through the LTE PGW using the internet address; the LTEnetwork configured, after the wireless communication device terminatescommunications with the WiFi network, to exchange second user databetween the wireless communication device and the internet through theLTE P-GW using the internet address but not the WiFi network.
 12. Thewireless communication system of claim 11 wherein the internet addressused to exchange the first user data and the internet address used toexchange the second user data comprise a same internet address.
 13. Thewireless communication system of claim 11 wherein the WiFi networkidentifier comprises a Service Set Identifier (SSID).
 14. The wirelesscommunication system of claim 11 wherein the LTE network is configuredto translate the WiFi network identifier into a geographic location ofthe WiFi network and translate the geographic location into a PGWidentifier.
 15. The wireless communication system of claim 11 whereinthe LTE network is configured to translate a Service Set Identifier(SSID) for the WiFi network into a PGW identifier.
 16. The wirelesscommunication system of claim 11 wherein the LTE network, is configuredto process a wireless communication device identifier in addition to theWiFi network identifier to select the LTE Packet Gateway (PGW).
 17. Thewireless communication system of claim 11 wherein the wirelesscommunication device terminates communications with the WiFi network inresponse to leaving WiFi network coverage.
 18. The wirelesscommunication system of claim 11 wherein the wireless communicationdevice terminates communications with the WiFi network in response to auser instruction to disable a WiFi transceiver.
 19. The wirelesscommunication system of claim 11 wherein the first user data and thesecond user data comprise a voice session.
 20. The wirelesscommunication system of claim 11 wherein the first user data and thesecond user data comprise a video session.